[PATCH v2 2/2] sunxi: Add option to prevent booting on power plug-in

[Andre Przywara]

From: Chris Morgan <macromorgan at hotmail.com>

For sunxi boards with the AXP209, AXP221, AXP809, and AXP818 PMICs
(plus possibly others, I only confirmed the datasheets for these),
it is sometimes desirable to not boot whenever the device is
plugged in. An example would be when using the NTC CHIP inside a
PocketCHIP.
This provides a configurable option to check if bit 0 of
register 0 of the PMIC says it was powered because of a power button
press (0) or a plug-in event (1). If the value is 1 and this option
is selected, the device shuts down shortly after printing a message
to console stating the reason why it's shutting down. Powering up the
board with the power button is not affected.

Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
[Andre: reword to speak of boot, remove #ifdefs]
Signed-off-by: Andre Przywara <andre.przywara at arm.com>

adapt board.c to generic AXP symbols
---
 arch/arm/mach-sunxi/Kconfig | 10 ++++++++++
 board/sunxi/board.c         | 11 +++++++++++
 2 files changed, 21 insertions(+)

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 2c18cf02d1..d7f9a03152 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -785,6 +785,16 @@ config AXP_GPIO
 	---help---
 	Say Y here to enable support for the gpio pins of the axp PMIC ICs.
 
+config AXP_DISABLE_BOOT_ON_POWERON
+	bool "Disable device boot on power plug-in"
+	depends on AXP209_POWER || AXP221_POWER || AXP809_POWER || AXP818_POWER
+	default n
+	---help---
+	  Say Y here to prevent the device from booting up because of a plug-in
+	  event. When set, the device will boot into the SPL briefly to
+	  determine why it was powered on, and if it was determined because of
+	  a plug-in event instead of a button press event it will shut back off.
+
 config VIDEO_SUNXI
 	bool "Enable graphical uboot console on HDMI, LCD or VGA"
 	depends on !MACH_SUN8I_A83T
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index fdbcd40269..3b5e7f3cdc 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -27,6 +27,7 @@
 #include <asm/arch/dram.h>
 #include <asm/arch/mmc.h>
 #include <asm/arch/prcm.h>
+#include <asm/arch/pmic_bus.h>
 #include <asm/arch/spl.h>
 #include <asm/global_data.h>
 #include <linux/delay.h>
@@ -601,6 +602,16 @@ void sunxi_board_init(void)
 	defined CONFIG_AXP809_POWER || defined CONFIG_AXP818_POWER
 	power_failed = axp_init();
 
+	if (IS_ENABLED(AXP_DISABLE_BOOT_ON_POWERON) && !power_failed) {
+		u8 boot_reason;
+
+		pmic_bus_read(AXP_POWER_STATUS, &boot_reason);
+		if (boot_reason & AXP_POWER_STATUS_ALDO_IN) {
+			printf("Power on by plug-in, shutting down.\n");
+			pmic_bus_write(0x32, BIT(7));
+		}
+	}
+
 #if defined CONFIG_AXP221_POWER || defined CONFIG_AXP809_POWER || \
 	defined CONFIG_AXP818_POWER
 	power_failed |= axp_set_dcdc1(CONFIG_AXP_DCDC1_VOLT);
-- 
2.25.1